Ionut Adrian Tanasoaia surrendered to police early Monday. He is accused of beating up Hardy in a bar in the southern Romanian city of Giurgiu on Saturday night.
Mediafax new agency reported Tanasoaia attacked Hardy because he wanted to dance with his girlfriend.
Hardy died shortly after undergoing surgery in a Bucharest hospital on Sunday. The 23-year-old player had sustained severe head injuries and was in a coma when he was admitted to the hospital.
Hardy played for CSS Giurgiu in southern Romania.